Monthly Archives: May 2014

solarmusic

Renewable Energy Around the World

Because of the fracking boom the United States has recently become the number one producer of natural gas, and is shooting for number one in oil production. The problem with this is two-fold. First, fossil fuel use contributes to global warming and a range of untoward health effects for both humans and the environment. Second, it is only a temporary solution to meeting our long term energy needs. We must develop truly sustainable energy supply for the future.

How are we doing on this front, especially with respect to our global economic competitors? Not so hot. One common argument for staying with the tried and true – but limited – fossil fuel industry is that it is the cheapest and therefore most economic resource base. This is only true if you completely ignore the cost of externalities such as cost to society of global warming and the cost of degraded health among the population.

There are many ways to measure a countries renewable energy production. Total produced, amount produced by various methodologies, percentage of total energy needs to mention just a few. Just about everybody needs electricity so for simplicity let’s compare renewable electrical energy production.

Countries with pronounced volcanic activity are well situated to produce geothermal energy. Iceland produces essentially 100 % of it electrical energy needs via geothermal processes. But Iceland is tiny, with a population not much larger than Little Rock.

Iceland geothermal

Iceland geothermal

Mountainous countries or those with with high rainfall have the potential for large amounts of hydropower. Norway produces over 100% of its electrical needs from hydropower. Excess power is exported to nearby European countries. Brazil has recently completed some large scale hydropower projects and now meets just over 90% of its needs. For comparison the United States produces about 7 % and China about 3 %.

Hydropower is a mature clean source of electrical energy so the developed countries have gone about as far as they can go with large scale hydropower. The real potential for expansion of renewable energy is wind and solar. First wind.

On a windy day Denmark, an island nation, can meet 100 % of its energy needs. On average however, they produce 30 % of electrical needs from wind and project to be at 50 % by 2020. The United States produces slightly more than 1 % and China slightly less than 1 % of total electrical energy production from wind.

Denmark wind

Denmark wind

Lastly but for the future maybe most importantly is solar. Current technology allows photovoltaic (PV) panels to capture about 15 % of the incident sunlight. By the way this is a couple of orders of magnitude more efficient than photosynthesis, so biomass is not considered in this analysis.

GermanVillageSolar

GermanVillageSolar

The world leader for solar is Germany where close to 5 % of their total electrical energy production comes from roof top solar arrays. The United States, 0.02 % and China 0.01 %. Our long term future on this planet depends to a large degree on our ability to develop sustainable energy supplies. Some countries, especially those in the western European community get it, the United States, not so much – at least not yet.

Seawater to Fuel?

The United States Navy recently announced that they had invented a process to turn sea water into fuel. It’s not exactly the water, but rather the water and Carbon Dioxide dissolved in the water which is turned into fuel.

Is this a game changer? Is it time to quit drilling for oil or digging for coal? No more nuclear reactors and the dangerous wastes, or even wind turbines, which kill so many birds and bats? No more deserts covered with solar panels? Hallelujah.

synthfuel

synthfuel

Scientists at the Naval Research Laboratory have found a way to extract Carbon Dioxide from the seawater, at the same time generating Hydrogen. These gases are then combined in the presence of a catalyst to become the equivalent of jet fuel.

Logistically this could be big for the Navy. Fuel could be produced while at sea lessening the risks of refueling in hostile waters. Remember the USS Cole? It was a guided missile destroyer that docked in Aden, Yemen for refueling. While there she was attacked by al-Qaeda resulting in the death of 17 sailors.

USS Cole

USS Cole

In addition to the production of jet fuel, with only slight modification of the process and or the catalyst, fuel for everything from cars to power plants to home heating oil can easily be produced. Seaside plants could churn out all the fuel the world needs right? Not exactly.

What has been neglected or at least not emphasized is the fact that the current process takes twice the electrical energy to produce the fuel as you get back when the fuel is burned. Bummer. It has been suggested that the process can be made more efficient. But there are absolute limits.

The first law of thermodynamics says, and I’m paraphrasing here – there is no such thing as a free lunch – when it comes to energy. The energy content of fossil fuels derive their energy from the sun. To make the fuel from sea water takes energy. But it gets worse, the second law of thermodynamics says you can’t even break even. There is no such thing as a 100 per cent efficient energy conversion process. There are always losses. Because of these simple laws, laws which can’t be broken, it will always take more energy than you get out in any energy conversion process.

Back to the navy. The process as noted may have logistical advantages, but it is no magic bullet for energy production. A ship at sea would have to supply energy, more than you get out, to produce the fuel. For fossil fuel powered ships this is a non-starter. Nuclear powered ships could use some of the nuclear power to generate electricity for the fuel production, but it would mean shorter durations between nuclear refueling.

Remember, there is no such thing as a free lunch, and you can’t even break even. Unlike Jaywalking or bank robbery, these laws can’t be broken.

tesla

Electric Cars’ Carbon Footprint

It seems inevitable that we will learn that burning stuff is not the best way to create the energy, the motive force, the warmth and the light we need for modern existence. Ultimately we will. Until then just what havoc we will wreak on the environment and our personal health is anybody’s question.

Combustion of fossil fuels produces numerous atmospheric pollutants directly harmful to health including respirable particulates, Carbon Monoxide, and Ozone. There are certainly more but just these three contribute mightily to lung and heart disease. The amounts of the various pollutants vary by source. Natural gas is the cleanest burning fuel followed by oil derived products such as gasoline and diesel. Coal is the dirtiest fuel. Burning coal releases not only the products of carbon combustion but also a slew of impurities. Toxic heavy metals top the list- Mercury, Cadmium, and Lead. To complete the picture sulfuric acid and nitric acid are released which cause acid rain.

100  year old electric car

100 year old electric car

Burning fossil fuels also produces Carbon Dioxide, the major global pollutant. The US supreme court ruled in 2007 that the Environmental Protection Agency has the authority and in fact duty to regulate it as a pollutant.

An obvious step to get away from fossil fuels is the use of electric cars powered by batteries charged from wind and solar power sources. But which comes first, the cars or the wind turbines? Actually some cars are already in production, including the Chevy Volt and Nissan leaf. The batteries in these cars can be charged by plugging a connector into an electrical outlet.

Chevy Volt

Chevy Volt

Many have questioned the use of an electric car if the electricity used to charge the batteries comes from the electrical grid which is powered mainly by fossil fuels. The grid is powered by 37 per cent coal, 30 percent natural gas, a scant 1% oil and the remainder from nuclear and renewables. Part of the energy used in an electric car does come from burning stuff, which is not good. But so does the car with the internal combustion engine.

The question then is which has the greater Carbon footprint? Internal combustion engines have been in use and incrementally improved for close to a century, yet only 20 percent of the energy in the fuel goes to move the car down the road. The rest goes to waste heat.

Nissan Leaf

Nissan Leaf

Electric motors have been around for quite a while too, but are much more efficient, around 90 percent efficient at converting the energy stored in a battery into moving the car down the road. A complete analysis shows that the carbon footprint of an electric car is lower than a gasoline or diesel powered vehicle, mainly do to the relative efficiencies.

Battery technology is major factor holding back the real penetration of electric cars in the market. The issue is one of energy density and cost. The amount of energy that can be stored in a battery of a given weight has been a problem. Tesla, an electric car company, is developing a battery manufacturing facility that should both lower costs and extend the range of Lithium Ion batteries for electric cars.

plains-and-eastern-clean-line-project

Health Effects of Power Lines

The proposal of a couple of high voltage electric power lines in northwest Arkansas has some concerned about health effects of those who may be living nearby. The larger of the two is a 750 kilovolt DC transmission line which will move excess electricity generated from wind turbines in Oklahoma and Kansas across Arkansas to connect with the Tennessee Valley Authority network in Memphis.

The health concern is all about exposure to electromagnetic fields (EMF) emanating from the power lines. Are there health effects? What are they? How close do you have to be? There is no question that those giant pylons with the looping wires are unsightly, and in the minds of some unnecessary, but are they a health risk? The short answer is more than likely not, but it will take some discussion.

First and foremost we are bathed in electromagnetic radiation from birth to death. The sun provides many forms; visible radiation (sunlight) by which we see. Infrared radiation from the sun warms us. Ultraviolet radiation tans us.

In addition to these natural forms of radiation we are exposed to man made electromagnetic radiation from radio, television, and cell phone transmissions. Electrical wiring and all electrical devices in the home create electromagnetic fields.

The evidence of harm from Power lines is scant and contradictory. It all started with a study in Denver in 1979. Researchers found a correlation between living near power lines and childhood leukemia, even though it is not biologically plausible. Basically what the researchers proved again that income correlates with cancer, and those who live near power lines are in a lower socioeconomic bracket.

Since that time there have been literally tens of thousands of peer reviewed studies which show no clear indication of harm. An important principle of toxicology, the science of poisons, is the dose response relationship. The greater the dose – the the greater the harm. Any of the studies which did suggest harm did not correlate with exposure.

Magnetic fields are measured in units of Gauss (G). For example the magnetic field in a medical diagnostic device called a MRI is huge, of the order of 70,000 G . There is no evidence of harm from MRI scans.

Other magnetic fields that we are exposed to include those from small electric devices in the home. A hair dryer in use produces a field strength thousands of times smaller, 20 G with a similar values for an electric razor. A refrigerator produces a field of about .02 G.

So what about a power line? The field strength drops off rapidly with distance from the source so the actual field strength under or near a power line is quite small. At a distance of 30 meters the field strength is a fraction of a thousandth of a Gauss (.004 G.) This is hundreds to thousands of times lower than exposures in average homes.

At the expense of repeating myself there is essentially no proof of either toxic or carcinogenic risks associated with living near power lines. Argue if you will that they are ugly, or that you don’t want them on your land, or that they aren’t necessary. Arguments about health effects however will fall on deaf ears.